Context: More than 80 countries fortify flour, yet the public health impact of this intervention on iron and anemia outcomes has not been reviewed.
Objective: The objective of this systematic review was to review published and gray literature pertaining to the impact of flour fortification on iron and anemia.
Data Sources: A systematic review was conducted by searching 17 databases and appealing for unpublished reports, yielding 1881 documents.
Study Selection: Only studies of government-supported, widely implemented fortification programs in which anemia or iron status was measured prior to and ≥12 months after initiation of fortification were included.
Data Extraction: Details about the design, coverage, compliance with national standards, and evaluation (e.g., anemia prevalence before and after fortification) of flour fortification programs were extracted from the reports.
Data Synthesis: Thirteen studies describing 26 subgroups (n = 14 for children ≤15 y, n = 12 for women of reproductive age) were included. During the period from pre- to postfortification (and as difference-in-difference for those studies that included a control group), there were statistically significant decreases in the prevalence of anemia in 4 of 13 subgroups of children and in 4 of 12 subgroups of women of reproductive age as well as significant decreases in the prevalence of low ferritin in 1 of 6 subgroups of children and in 3 of 3 subgroups of women of reproductive age.
Conclusions: Evidence of the effectiveness of flour fortification for reducing the prevalence of anemia is limited; however, evidence of effectiveness for reducing the prevalence of low ferritin in women is more consistent.